/* linenoise.c -- guerrilla line editing library against the idea that a
 * line editing lib needs to be 20,000 lines of C code.
 *
 * You can find the latest source code at:
 *
 *   http://github.com/antirez/linenoise
 *
 * Does a number of crazy assumptions that happen to be true in 99.9999% of
 * the 2010 UNIX computers around.
 *
 * ------------------------------------------------------------------------
 *
 * Copyright (c) 2010-2023, Salvatore Sanfilippo <antirez at gmail dot com>
 * Copyright (c) 2010-2013, Pieter Noordhuis <pcnoordhuis at gmail dot com>
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *  *  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *  *  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * ------------------------------------------------------------------------
 *
 * References:
 * - http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
 * - http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html
 *
 * Todo list:
 * - Filter bogus Ctrl+<char> combinations.
 * - Win32 support
 *
 * Bloat:
 * - History search like Ctrl+r in readline?
 *
 * List of escape sequences used by this program, we do everything just
 * with three sequences. In order to be so cheap we may have some
 * flickering effect with some slow terminal, but the lesser sequences
 * the more compatible.
 *
 * EL (Erase Line)
 *    Sequence: ESC [ n K
 *    Effect: if n is 0 or missing, clear from cursor to end of line
 *    Effect: if n is 1, clear from beginning of line to cursor
 *    Effect: if n is 2, clear entire line
 *
 * CUF (CUrsor Forward)
 *    Sequence: ESC [ n C
 *    Effect: moves cursor forward n chars
 *
 * CUB (CUrsor Backward)
 *    Sequence: ESC [ n D
 *    Effect: moves cursor backward n chars
 *
 * The following is used to get the terminal width if getting
 * the width with the TIOCGWINSZ ioctl fails
 *
 * DSR (Device Status Report)
 *    Sequence: ESC [ 6 n
 *    Effect: reports the current cusor position as ESC [ n ; m R
 *            where n is the row and m is the column
 *
 * When multi line mode is enabled, we also use an additional escape
 * sequence. However multi line editing is disabled by default.
 *
 * CUU (Cursor Up)
 *    Sequence: ESC [ n A
 *    Effect: moves cursor up of n chars.
 *
 * CUD (Cursor Down)
 *    Sequence: ESC [ n B
 *    Effect: moves cursor down of n chars.
 *
 * When linenoiseClearScreen() is called, two additional escape sequences
 * are used in order to clear the screen and position the cursor at home
 * position.
 *
 * CUP (Cursor position)
 *    Sequence: ESC [ H
 *    Effect: moves the cursor to upper left corner
 *
 * ED (Erase display)
 *    Sequence: ESC [ 2 J
 *    Effect: clear the whole screen
 *
 */

#include "Linenoise.h"

#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <termios.h>
#include <unistd.h>

#define LINENOISE_DEFAULT_HISTORY_MAX_LEN 100
#define LINENOISE_MAX_LINE 4096
static char *unsupported_term[] = {"dumb", "cons25", "emacs", NULL};
static linenoiseCompletionCallback *completionCallback = NULL;
static linenoiseHintsCallback *hintsCallback = NULL;
static linenoiseFreeHintsCallback *freeHintsCallback = NULL;
static char *linenoiseNoTTY(void);
static void refreshLineWithCompletion(struct linenoiseState *ls, linenoiseCompletions *lc, int flags);
static void refreshLineWithFlags(struct linenoiseState *l, int flags);

static struct termios orig_termios; /* In order to restore at exit.*/
static int maskmode = 0;            /* Show "***" instead of input. For passwords. */
static int rawmode = 0;             /* For atexit() function to check if restore is needed*/
static int mlmode = 0;              /* Multi line mode. Default is single line. */
static int atexit_registered = 0;   /* Register atexit just 1 time. */
static int history_max_len = LINENOISE_DEFAULT_HISTORY_MAX_LEN;
static int history_len = 0;
static char **history = NULL;

enum KEY_ACTION {
  KEY_NULL = 0,   /* NULL */
  CTRL_A = 1,     /* Ctrl+a */
  CTRL_B = 2,     /* Ctrl-b */
  CTRL_C = 3,     /* Ctrl-c */
  CTRL_D = 4,     /* Ctrl-d */
  CTRL_E = 5,     /* Ctrl-e */
  CTRL_F = 6,     /* Ctrl-f */
  CTRL_H = 8,     /* Ctrl-h */
  TAB = 9,        /* Tab */
  CTRL_K = 11,    /* Ctrl+k */
  CTRL_L = 12,    /* Ctrl+l */
  ENTER = 13,     /* Enter */
  CTRL_N = 14,    /* Ctrl-n */
  CTRL_P = 16,    /* Ctrl-p */
  CTRL_T = 20,    /* Ctrl-t */
  CTRL_U = 21,    /* Ctrl+u */
  CTRL_W = 23,    /* Ctrl+w */
  ESC = 27,       /* Escape */
  BACKSPACE = 127 /* Backspace */
};

static void linenoiseAtExit(void);
int linenoiseHistoryAdd(const char *line);
#define REFRESH_CLEAN (1 << 0)                       // Clean the old prompt from the screen
#define REFRESH_WRITE (1 << 1)                       // Rewrite the prompt on the screen.
#define REFRESH_ALL (REFRESH_CLEAN | REFRESH_WRITE)  // Do both.
static void refreshLine(struct linenoiseState *l);

/* Debugging macro. */
#if 0
FILE *lndebug_fp = NULL;
#define lndebug(...)                                                         \
  do {                                                                       \
    if (lndebug_fp == NULL) {                                                \
      lndebug_fp = fopen("/tmp/lndebug.txt", "a");                           \
      fprintf(lndebug_fp,                                                    \
              "[%d %d %d] p: %d, rows: %d, rpos: %d, max: %d, oldmax: %d\n", \
              (int)l->len,                                                   \
              (int)l->pos,                                                   \
              (int)l->oldpos,                                                \
              plen,                                                          \
              rows,                                                          \
              rpos,                                                          \
              (int)l->oldrows,                                               \
              old_rows);                                                     \
    }                                                                        \
    fprintf(lndebug_fp, ", " __VA_ARGS__);                                   \
    fflush(lndebug_fp);                                                      \
  } while (0)
#else
#define lndebug(fmt, ...)
#endif

/* ======================= Low level terminal handling ====================== */

/* Enable "mask mode". When it is enabled, instead of the input that
 * the user is typing, the terminal will just display a corresponding
 * number of asterisks, like "****". This is useful for passwords and other
 * secrets that should not be displayed. */
void linenoiseMaskModeEnable(void) { maskmode = 1; }

/* Disable mask mode. */
void linenoiseMaskModeDisable(void) { maskmode = 0; }

/* Set if to use or not the multi line mode. */
void linenoiseSetMultiLine(int ml) { mlmode = ml; }

/* Return true if the terminal name is in the list of terminals we know are
 * not able to understand basic escape sequences. */
static int isUnsupportedTerm(void) {
  char *term = getenv("TERM");
  int j;

  if (term == NULL) return 0;
  for (j = 0; unsupported_term[j]; j++)
    if (!strcasecmp(term, unsupported_term[j])) return 1;
  return 0;
}

/* Raw mode: 1960 magic shit. */
static int enableRawMode(int fd) {
  struct termios raw;

  if (!isatty(STDIN_FILENO)) goto fatal;
  if (!atexit_registered) {
    atexit(linenoiseAtExit);
    atexit_registered = 1;
  }
  if (tcgetattr(fd, &orig_termios) == -1) goto fatal;

  raw = orig_termios; /* modify the original mode */
  /* input modes: no break, no CR to NL, no parity check, no strip char,
   * no start/stop output control. */
  raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
  /* output modes - disable post processing */
  raw.c_oflag &= ~(OPOST);
  /* control modes - set 8 bit chars */
  raw.c_cflag |= (CS8);
  /* local modes - choing off, canonical off, no extended functions,
   * no signal chars (^Z,^C) */
  raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
  /* control chars - set return condition: min number of bytes and timer.
   * We want read to return every single byte, without timeout. */
  raw.c_cc[VMIN] = 1;
  raw.c_cc[VTIME] = 0; /* 1 byte, no timer */

  /* put terminal in raw mode after flushing */
  if (tcsetattr(fd, TCSAFLUSH, &raw) < 0) goto fatal;
  rawmode = 1;
  return 0;

fatal:
  errno = ENOTTY;
  return -1;
}

static void disableRawMode(int fd) {
  /* Don't even check the return value as it's too late. */
  if (rawmode && tcsetattr(fd, TCSAFLUSH, &orig_termios) != -1) rawmode = 0;
}

/* Use the ESC [6n escape sequence to query the horizontal cursor position
 * and return it. On error -1 is returned, on success the position of the
 * cursor. */
static int getCursorPosition(int ifd, int ofd) {
  char buf[32];
  int cols, rows;
  unsigned int i = 0;

  /* Report cursor location */
  if (write(ofd, "\x1b[6n", 4) != 4) return -1;

  /* Read the response: ESC [ rows ; cols R */
  while (i < sizeof(buf) - 1) {
    if (read(ifd, buf + i, 1) != 1) break;
    if (buf[i] == 'R') break;
    i++;
  }
  buf[i] = '\0';

  /* Parse it. */
  if (buf[0] != ESC || buf[1] != '[') return -1;
  if (sscanf(buf + 2, "%d;%d", &rows, &cols) != 2) return -1;
  return cols;
}

/* Try to get the number of columns in the current terminal, or assume 80
 * if it fails. */
static int getColumns(int ifd, int ofd) {
  struct winsize ws;

  if (ioctl(1, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0) {
    /* ioctl() failed. Try to query the terminal itself. */
    int start, cols;

    /* Get the initial position so we can restore it later. */
    start = getCursorPosition(ifd, ofd);
    if (start == -1) goto failed;

    /* Go to right margin and get position. */
    if (write(ofd, "\x1b[999C", 6) != 6) goto failed;
    cols = getCursorPosition(ifd, ofd);
    if (cols == -1) goto failed;

    /* Restore position. */
    if (cols > start) {
      char seq[32];
      snprintf(seq, 32, "\x1b[%dD", cols - start);
      if (write(ofd, seq, strlen(seq)) == -1) {
        /* Can't recover... */
      }
    }
    return cols;
  } else {
    return ws.ws_col;
  }

failed:
  return 80;
}

/* Clear the screen. Used to handle ctrl+l */
void linenoiseClearScreen(void) {
  if (write(STDOUT_FILENO, "\x1b[H\x1b[2J", 7) <= 0) {
    /* nothing to do, just to avoid warning. */
  }
}

/* Beep, used for completion when there is nothing to complete or when all
 * the choices were already shown. */
static void linenoiseBeep(void) {
  fprintf(stderr, "\x7");
  fflush(stderr);
}

/* ============================== Completion ================================ */

/* Free a list of completion option populated by linenoiseAddCompletion(). */
static void freeCompletions(linenoiseCompletions *lc) {
  size_t i;
  for (i = 0; i < lc->len; i++) free(lc->cvec[i]);
  if (lc->cvec != NULL) free(lc->cvec);
}

/* Called by completeLine() and linenoiseShow() to render the current
 * edited line with the proposed completion. If the current completion table
 * is already available, it is passed as second argument, otherwise the
 * function will use the callback to obtain it.
 *
 * Flags are the same as refreshLine*(), that is REFRESH_* macros. */
static void refreshLineWithCompletion(struct linenoiseState *ls, linenoiseCompletions *lc, int flags) {
  /* Obtain the table of completions if the caller didn't provide one. */
  linenoiseCompletions ctable = {0, NULL};
  if (lc == NULL) {
    completionCallback(ls->buf, &ctable);
    lc = &ctable;
  }

  /* Show the edited line with completion if possible, or just refresh. */
  if (ls->completion_idx < lc->len) {
    struct linenoiseState saved = *ls;
    ls->len = ls->pos = strlen(lc->cvec[ls->completion_idx]);
    ls->buf = lc->cvec[ls->completion_idx];
    refreshLineWithFlags(ls, flags);
    ls->len = saved.len;
    ls->pos = saved.pos;
    ls->buf = saved.buf;
  } else {
    refreshLineWithFlags(ls, flags);
  }

  /* Free the completions table if needed. */
  if (lc != &ctable) freeCompletions(&ctable);
}

/* This is an helper function for linenoiseEdit*() and is called when the
 * user types the <tab> key in order to complete the string currently in the
 * input.
 *
 * The state of the editing is encapsulated into the pointed linenoiseState
 * structure as described in the structure definition.
 *
 * If the function returns non-zero, the caller should handle the
 * returned value as a byte read from the standard input, and process
 * it as usually: this basically means that the function may return a byte
 * read from the termianl but not processed. Otherwise, if zero is returned,
 * the input was consumed by the completeLine() function to navigate the
 * possible completions, and the caller should read for the next characters
 * from stdin. */
static int completeLine(struct linenoiseState *ls, int keypressed) {
  linenoiseCompletions lc = {0, NULL};
  int nwritten;
  char c = keypressed;

  completionCallback(ls->buf, &lc);
  if (lc.len == 0) {
    linenoiseBeep();
    ls->in_completion = 0;
  } else {
    switch (c) {
      case 9: /* tab */
        if (ls->in_completion == 0) {
          ls->in_completion = 1;
          ls->completion_idx = 0;
        } else {
          ls->completion_idx = (ls->completion_idx + 1) % (lc.len + 1);
          if (ls->completion_idx == lc.len) linenoiseBeep();
        }
        c = 0;
        break;
      case 27: /* escape */
        /* Re-show original buffer */
        if (ls->completion_idx < lc.len) refreshLine(ls);
        ls->in_completion = 0;
        c = 0;
        break;
      default:
        /* Update buffer and return */
        if (ls->completion_idx < lc.len) {
          nwritten = snprintf(ls->buf, ls->buflen, "%s", lc.cvec[ls->completion_idx]);
          ls->len = ls->pos = nwritten;
        }
        ls->in_completion = 0;
        break;
    }

    /* Show completion or original buffer */
    if (ls->in_completion && ls->completion_idx < lc.len) {
      refreshLineWithCompletion(ls, &lc, REFRESH_ALL);
    } else {
      refreshLine(ls);
    }
  }

  freeCompletions(&lc);
  return c; /* Return last read character */
}

/* Register a callback function to be called for tab-completion. */
void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) { completionCallback = fn; }

/* Register a hits function to be called to show hits to the user at the
 * right of the prompt. */
void linenoiseSetHintsCallback(linenoiseHintsCallback *fn) { hintsCallback = fn; }

/* Register a function to free the hints returned by the hints callback
 * registered with linenoiseSetHintsCallback(). */
void linenoiseSetFreeHintsCallback(linenoiseFreeHintsCallback *fn) { freeHintsCallback = fn; }

/* This function is used by the callback function registered by the user
 * in order to add completion options given the input string when the
 * user typed <tab>. See the example.c source code for a very easy to
 * understand example. */
void linenoiseAddCompletion(linenoiseCompletions *lc, const char *str) {
  size_t len = strlen(str);
  char *copy, **cvec;

  copy = malloc(len + 1);
  if (copy == NULL) return;
  memcpy(copy, str, len + 1);
  cvec = realloc(lc->cvec, sizeof(char *) * (lc->len + 1));
  if (cvec == NULL) {
    free(copy);
    return;
  }
  lc->cvec = cvec;
  lc->cvec[lc->len++] = copy;
}

/* =========================== Line editing ================================= */

/* We define a very simple "append buffer" structure, that is an heap
 * allocated string where we can append to. This is useful in order to
 * write all the escape sequences in a buffer and flush them to the standard
 * output in a single call, to avoid flickering effects. */
struct abuf {
  char *b;
  int len;
};

static void abInit(struct abuf *ab) {
  ab->b = NULL;
  ab->len = 0;
}

static void abAppend(struct abuf *ab, const char *s, int len) {
  char *new = realloc(ab->b, ab->len + len);

  if (new == NULL) return;
  memcpy(new + ab->len, s, len);
  ab->b = new;
  ab->len += len;
}

static void abFree(struct abuf *ab) { free(ab->b); }

/* Helper of refreshSingleLine() and refreshMultiLine() to show hints
 * to the right of the prompt. */
void refreshShowHints(struct abuf *ab, struct linenoiseState *l, int plen) {
  char seq[64];
  if (hintsCallback && plen + l->len < l->cols) {
    int color = -1, bold = 0;
    char *hint = hintsCallback(l->buf, &color, &bold);
    if (hint) {
      int hintlen = strlen(hint);
      int hintmaxlen = l->cols - (plen + l->len);
      if (hintlen > hintmaxlen) hintlen = hintmaxlen;
      if (bold == 1 && color == -1) color = 37;
      if (color != -1 || bold != 0)
        snprintf(seq, 64, "\033[%d;%d;49m", bold, color);
      else
        seq[0] = '\0';
      abAppend(ab, seq, strlen(seq));
      abAppend(ab, hint, hintlen);
      if (color != -1 || bold != 0) abAppend(ab, "\033[0m", 4);
      /* Call the function to free the hint returned. */
      if (freeHintsCallback) freeHintsCallback(hint);
    }
  }
}

/* Single line low level line refresh.
 *
 * Rewrite the currently edited line accordingly to the buffer content,
 * cursor position, and number of columns of the terminal.
 *
 * Flags is REFRESH_* macros. The function can just remove the old
 * prompt, just write it, or both. */
static void refreshSingleLine(struct linenoiseState *l, int flags) {
  char seq[64];
  size_t plen = strlen(l->prompt);
  int fd = l->ofd;
  char *buf = l->buf;
  size_t len = l->len;
  size_t pos = l->pos;
  struct abuf ab;

  while ((plen + pos) >= l->cols) {
    buf++;
    len--;
    pos--;
  }
  while (plen + len > l->cols) {
    len--;
  }

  abInit(&ab);
  /* Cursor to left edge */
  snprintf(seq, sizeof(seq), "\r");
  abAppend(&ab, seq, strlen(seq));

  if (flags & REFRESH_WRITE) {
    /* Write the prompt and the current buffer content */
    abAppend(&ab, l->prompt, strlen(l->prompt));
    if (maskmode == 1) {
      while (len--) abAppend(&ab, "*", 1);
    } else {
      abAppend(&ab, buf, len);
    }
    /* Show hits if any. */
    refreshShowHints(&ab, l, plen);
  }

  /* Erase to right */
  snprintf(seq, sizeof(seq), "\x1b[0K");
  abAppend(&ab, seq, strlen(seq));

  if (flags & REFRESH_WRITE) {
    /* Move cursor to original position. */
    snprintf(seq, sizeof(seq), "\r\x1b[%dC", (int)(pos + plen));
    abAppend(&ab, seq, strlen(seq));
  }

  if (write(fd, ab.b, ab.len) == -1) {
  } /* Can't recover from write error. */
  abFree(&ab);
}

/* Multi line low level line refresh.
 *
 * Rewrite the currently edited line accordingly to the buffer content,
 * cursor position, and number of columns of the terminal.
 *
 * Flags is REFRESH_* macros. The function can just remove the old
 * prompt, just write it, or both. */
static void refreshMultiLine(struct linenoiseState *l, int flags) {
  char seq[64];
  int plen = strlen(l->prompt);
  int rows = (plen + l->len + l->cols - 1) / l->cols; /* rows used by current buf. */
  int rpos = (plen + l->oldpos + l->cols) / l->cols;  /* cursor relative row. */
  int rpos2;                                          /* rpos after refresh. */
  int col;                                            /* column position, zero-based. */
  int old_rows = l->oldrows;
  int fd = l->ofd, j;
  struct abuf ab;

  l->oldrows = rows;

  /* First step: clear all the lines used before. To do so start by
   * going to the last row. */
  abInit(&ab);

  if (flags & REFRESH_CLEAN) {
    if (old_rows - rpos > 0) {
      lndebug("go down %d", old_rows - rpos);
      snprintf(seq, 64, "\x1b[%dB", old_rows - rpos);
      abAppend(&ab, seq, strlen(seq));
    }

    /* Now for every row clear it, go up. */
    for (j = 0; j < old_rows - 1; j++) {
      lndebug("clear+up");
      snprintf(seq, 64, "\r\x1b[0K\x1b[1A");
      abAppend(&ab, seq, strlen(seq));
    }
  }

  if (flags & REFRESH_ALL) {
    /* Clean the top line. */
    lndebug("clear");
    snprintf(seq, 64, "\r\x1b[0K");
    abAppend(&ab, seq, strlen(seq));
  }

  if (flags & REFRESH_WRITE) {
    /* Write the prompt and the current buffer content */
    abAppend(&ab, l->prompt, strlen(l->prompt));
    if (maskmode == 1) {
      unsigned int i;
      for (i = 0; i < l->len; i++) abAppend(&ab, "*", 1);
    } else {
      abAppend(&ab, l->buf, l->len);
    }

    /* Show hits if any. */
    refreshShowHints(&ab, l, plen);

    /* If we are at the very end of the screen with our prompt, we need to
     * emit a newline and move the prompt to the first column. */
    if (l->pos && l->pos == l->len && (l->pos + plen) % l->cols == 0) {
      lndebug("<newline>");
      abAppend(&ab, "\n", 1);
      snprintf(seq, 64, "\r");
      abAppend(&ab, seq, strlen(seq));
      rows++;
      if (rows > (int)l->oldrows) l->oldrows = rows;
    }

    /* Move cursor to right position. */
    rpos2 = (plen + l->pos + l->cols) / l->cols; /* Current cursor relative row */
    lndebug("rpos2 %d", rpos2);

    /* Go up till we reach the expected positon. */
    if (rows - rpos2 > 0) {
      lndebug("go-up %d", rows - rpos2);
      snprintf(seq, 64, "\x1b[%dA", rows - rpos2);
      abAppend(&ab, seq, strlen(seq));
    }

    /* Set column. */
    col = (plen + (int)l->pos) % (int)l->cols;
    lndebug("set col %d", 1 + col);
    if (col)
      snprintf(seq, 64, "\r\x1b[%dC", col);
    else
      snprintf(seq, 64, "\r");
    abAppend(&ab, seq, strlen(seq));
  }

  lndebug("\n");
  l->oldpos = l->pos;

  if (write(fd, ab.b, ab.len) == -1) {
  } /* Can't recover from write error. */
  abFree(&ab);
}

/* Calls the two low level functions refreshSingleLine() or
 * refreshMultiLine() according to the selected mode. */
static void refreshLineWithFlags(struct linenoiseState *l, int flags) {
  if (mlmode)
    refreshMultiLine(l, flags);
  else
    refreshSingleLine(l, flags);
}

/* Utility function to avoid specifying REFRESH_ALL all the times. */
static void refreshLine(struct linenoiseState *l) { refreshLineWithFlags(l, REFRESH_ALL); }

/* Hide the current line, when using the multiplexing API. */
void linenoiseHide(struct linenoiseState *l) {
  if (mlmode)
    refreshMultiLine(l, REFRESH_CLEAN);
  else
    refreshSingleLine(l, REFRESH_CLEAN);
}

/* Show the current line, when using the multiplexing API. */
void linenoiseShow(struct linenoiseState *l) {
  if (l->in_completion) {
    refreshLineWithCompletion(l, NULL, REFRESH_WRITE);
  } else {
    refreshLineWithFlags(l, REFRESH_WRITE);
  }
}

/* Insert the character 'c' at cursor current position.
 *
 * On error writing to the terminal -1 is returned, otherwise 0. */
int linenoiseEditInsert(struct linenoiseState *l, char c) {
  if (l->len < l->buflen) {
    if (l->len == l->pos) {
      l->buf[l->pos] = c;
      l->pos++;
      l->len++;
      l->buf[l->len] = '\0';
      if ((!mlmode && l->plen + l->len < l->cols && !hintsCallback)) {
        /* Avoid a full update of the line in the
         * trivial case. */
        char d = (maskmode == 1) ? '*' : c;
        if (write(l->ofd, &d, 1) == -1) return -1;
      } else {
        refreshLine(l);
      }
    } else {
      memmove(l->buf + l->pos + 1, l->buf + l->pos, l->len - l->pos);
      l->buf[l->pos] = c;
      l->len++;
      l->pos++;
      l->buf[l->len] = '\0';
      refreshLine(l);
    }
  }
  return 0;
}

/* Move cursor on the left. */
void linenoiseEditMoveLeft(struct linenoiseState *l) {
  if (l->pos > 0) {
    l->pos--;
    refreshLine(l);
  }
}

/* Move cursor on the right. */
void linenoiseEditMoveRight(struct linenoiseState *l) {
  if (l->pos != l->len) {
    l->pos++;
    refreshLine(l);
  }
}

/* Move cursor to the start of the line. */
void linenoiseEditMoveHome(struct linenoiseState *l) {
  if (l->pos != 0) {
    l->pos = 0;
    refreshLine(l);
  }
}

/* Move cursor to the end of the line. */
void linenoiseEditMoveEnd(struct linenoiseState *l) {
  if (l->pos != l->len) {
    l->pos = l->len;
    refreshLine(l);
  }
}

/* Substitute the currently edited line with the next or previous history
 * entry as specified by 'dir'. */
#define LINENOISE_HISTORY_NEXT 0
#define LINENOISE_HISTORY_PREV 1
void linenoiseEditHistoryNext(struct linenoiseState *l, int dir) {
  if (history_len > 1) {
    /* Update the current history entry before to
     * overwrite it with the next one. */
    free(history[history_len - 1 - l->history_index]);
    history[history_len - 1 - l->history_index] = strdup(l->buf);
    /* Show the new entry */
    l->history_index += (dir == LINENOISE_HISTORY_PREV) ? 1 : -1;
    if (l->history_index < 0) {
      l->history_index = 0;
      return;
    } else if (l->history_index >= history_len) {
      l->history_index = history_len - 1;
      return;
    }
    strncpy(l->buf, history[history_len - 1 - l->history_index], l->buflen);
    l->buf[l->buflen - 1] = '\0';
    l->len = l->pos = strlen(l->buf);
    refreshLine(l);
  }
}

/* Delete the character at the right of the cursor without altering the cursor
 * position. Basically this is what happens with the "Delete" keyboard key. */
void linenoiseEditDelete(struct linenoiseState *l) {
  if (l->len > 0 && l->pos < l->len) {
    memmove(l->buf + l->pos, l->buf + l->pos + 1, l->len - l->pos - 1);
    l->len--;
    l->buf[l->len] = '\0';
    refreshLine(l);
  }
}

/* Backspace implementation. */
void linenoiseEditBackspace(struct linenoiseState *l) {
  if (l->pos > 0 && l->len > 0) {
    memmove(l->buf + l->pos - 1, l->buf + l->pos, l->len - l->pos);
    l->pos--;
    l->len--;
    l->buf[l->len] = '\0';
    refreshLine(l);
  }
}

/* Delete the previosu word, maintaining the cursor at the start of the
 * current word. */
void linenoiseEditDeletePrevWord(struct linenoiseState *l) {
  size_t old_pos = l->pos;
  size_t diff;

  while (l->pos > 0 && l->buf[l->pos - 1] == ' ') l->pos--;
  while (l->pos > 0 && l->buf[l->pos - 1] != ' ') l->pos--;
  diff = old_pos - l->pos;
  memmove(l->buf + l->pos, l->buf + old_pos, l->len - old_pos + 1);
  l->len -= diff;
  refreshLine(l);
}

/* This function is part of the multiplexed API of Linenoise, that is used
 * in order to implement the blocking variant of the API but can also be
 * called by the user directly in an event driven program. It will:
 *
 * 1. Initialize the linenoise state passed by the user.
 * 2. Put the terminal in RAW mode.
 * 3. Show the prompt.
 * 4. Return control to the user, that will have to call linenoiseEditFeed()
 *    each time there is some data arriving in the standard input.
 *
 * The user can also call linenoiseEditHide() and linenoiseEditShow() if it
 * is required to show some input arriving asyncronously, without mixing
 * it with the currently edited line.
 *
 * When linenoiseEditFeed() returns non-NULL, the user finished with the
 * line editing session (pressed enter CTRL-D/C): in this case the caller
 * needs to call linenoiseEditStop() to put back the terminal in normal
 * mode. This will not destroy the buffer, as long as the linenoiseState
 * is still valid in the context of the caller.
 *
 * The function returns 0 on success, or -1 if writing to standard output
 * fails. If stdin_fd or stdout_fd are set to -1, the default is to use
 * STDIN_FILENO and STDOUT_FILENO.
 */
int linenoiseEditStart(struct linenoiseState *l,
                       int stdin_fd,
                       int stdout_fd,
                       char *buf,
                       size_t buflen,
                       const char *prompt) {
  /* Populate the linenoise state that we pass to functions implementing
   * specific editing functionalities. */
  l->in_completion = 0;
  l->ifd = stdin_fd != -1 ? stdin_fd : STDIN_FILENO;
  l->ofd = stdout_fd != -1 ? stdout_fd : STDOUT_FILENO;
  l->buf = buf;
  l->buflen = buflen;
  l->prompt = prompt;
  l->plen = strlen(prompt);
  l->oldpos = l->pos = 0;
  l->len = 0;
  l->cols = getColumns(stdin_fd, stdout_fd);
  l->oldrows = 0;
  l->history_index = 0;

  /* Buffer starts empty. */
  l->buf[0] = '\0';
  l->buflen--; /* Make sure there is always space for the nulterm */

  /* If stdin is not a tty, stop here with the initialization. We
   * will actually just read a line from standard input in blocking
   * mode later, in linenoiseEditFeed(). */
  if (!isatty(l->ifd)) return 0;

  /* Enter raw mode. */
  if (enableRawMode(l->ifd) == -1) return -1;

  /* The latest history entry is always our current buffer, that
   * initially is just an empty string. */
  linenoiseHistoryAdd("");

  if (write(l->ofd, prompt, l->plen) == -1) return -1;
  return 0;
}

char *linenoiseEditMore =
    "If you see this, you are misusing the API: when linenoiseEditFeed() is called, if it returns linenoiseEditMore "
    "the user is yet editing the line. See the README file for more information.";

/* This function is part of the multiplexed API of linenoise, see the top
 * comment on linenoiseEditStart() for more information. Call this function
 * each time there is some data to read from the standard input file
 * descriptor. In the case of blocking operations, this function can just be
 * called in a loop, and block.
 *
 * The function returns linenoiseEditMore to signal that line editing is still
 * in progress, that is, the user didn't yet pressed enter / CTRL-D. Otherwise
 * the function returns the pointer to the heap-allocated buffer with the
 * edited line, that the user should free with linenoiseFree().
 *
 * On special conditions, NULL is returned and errno is populated:
 *
 * EAGAIN if the user pressed Ctrl-C
 * ENOENT if the user pressed Ctrl-D
 *
 * Some other errno: I/O error.
 */
char *linenoiseEditFeed(struct linenoiseState *l) {
  /* Not a TTY, pass control to line reading without character
   * count limits. */
  if (!isatty(l->ifd)) return linenoiseNoTTY();

  char c;
  int nread;
  char seq[3];

  nread = read(l->ifd, &c, 1);
  if (nread <= 0) return NULL;

  /* Only autocomplete when the callback is set. It returns < 0 when
   * there was an error reading from fd. Otherwise it will return the
   * character that should be handled next. */
  if ((l->in_completion || c == 9) && completionCallback != NULL) {
    c = completeLine(l, c);
    /* Return on errors */
    if (c < 0) return NULL;
    /* Read next character when 0 */
    if (c == 0) return linenoiseEditMore;
  }

  switch (c) {
    case ENTER: /* enter */
      history_len--;
      free(history[history_len]);
      if (mlmode) linenoiseEditMoveEnd(l);
      if (hintsCallback) {
        /* Force a refresh without hints to leave the previous
         * line as the user typed it after a newline. */
        linenoiseHintsCallback *hc = hintsCallback;
        hintsCallback = NULL;
        refreshLine(l);
        hintsCallback = hc;
      }
      return strdup(l->buf);
    case CTRL_C: /* ctrl-c */
      errno = EAGAIN;
      return NULL;
    case BACKSPACE: /* backspace */
    case 8:         /* ctrl-h */
      linenoiseEditBackspace(l);
      break;
    case CTRL_D: /* ctrl-d, remove char at right of cursor, or if the
                    line is empty, act as end-of-file. */
      if (l->len > 0) {
        linenoiseEditDelete(l);
      } else {
        history_len--;
        free(history[history_len]);
        errno = ENOENT;
        return NULL;
      }
      break;
    case CTRL_T: /* ctrl-t, swaps current character with previous. */
      if (l->pos > 0 && l->pos < l->len) {
        int aux = l->buf[l->pos - 1];
        l->buf[l->pos - 1] = l->buf[l->pos];
        l->buf[l->pos] = aux;
        if (l->pos != l->len - 1) l->pos++;
        refreshLine(l);
      }
      break;
    case CTRL_B: /* ctrl-b */
      linenoiseEditMoveLeft(l);
      break;
    case CTRL_F: /* ctrl-f */
      linenoiseEditMoveRight(l);
      break;
    case CTRL_P: /* ctrl-p */
      linenoiseEditHistoryNext(l, LINENOISE_HISTORY_PREV);
      break;
    case CTRL_N: /* ctrl-n */
      linenoiseEditHistoryNext(l, LINENOISE_HISTORY_NEXT);
      break;
    case ESC: /* escape sequence */
      /* Read the next two bytes representing the escape sequence.
       * Use two calls to handle slow terminals returning the two
       * chars at different times. */
      if (read(l->ifd, seq, 1) == -1) break;
      if (read(l->ifd, seq + 1, 1) == -1) break;

      /* ESC [ sequences. */
      if (seq[0] == '[') {
        if (seq[1] >= '0' && seq[1] <= '9') {
          /* Extended escape, read additional byte. */
          if (read(l->ifd, seq + 2, 1) == -1) break;
          if (seq[2] == '~') {
            switch (seq[1]) {
              case '3': /* Delete key. */
                linenoiseEditDelete(l);
                break;
            }
          }
        } else {
          switch (seq[1]) {
            case 'A': /* Up */
              linenoiseEditHistoryNext(l, LINENOISE_HISTORY_PREV);
              break;
            case 'B': /* Down */
              linenoiseEditHistoryNext(l, LINENOISE_HISTORY_NEXT);
              break;
            case 'C': /* Right */
              linenoiseEditMoveRight(l);
              break;
            case 'D': /* Left */
              linenoiseEditMoveLeft(l);
              break;
            case 'H': /* Home */
              linenoiseEditMoveHome(l);
              break;
            case 'F': /* End*/
              linenoiseEditMoveEnd(l);
              break;
          }
        }
      }

      /* ESC O sequences. */
      else if (seq[0] == 'O') {
        switch (seq[1]) {
          case 'H': /* Home */
            linenoiseEditMoveHome(l);
            break;
          case 'F': /* End*/
            linenoiseEditMoveEnd(l);
            break;
        }
      }
      break;
    default:
      if (linenoiseEditInsert(l, c)) return NULL;
      break;
    case CTRL_U: /* Ctrl+u, delete the whole line. */
      l->buf[0] = '\0';
      l->pos = l->len = 0;
      refreshLine(l);
      break;
    case CTRL_K: /* Ctrl+k, delete from current to end of line. */
      l->buf[l->pos] = '\0';
      l->len = l->pos;
      refreshLine(l);
      break;
    case CTRL_A: /* Ctrl+a, go to the start of the line */
      linenoiseEditMoveHome(l);
      break;
    case CTRL_E: /* ctrl+e, go to the end of the line */
      linenoiseEditMoveEnd(l);
      break;
    case CTRL_L: /* ctrl+l, clear screen */
      linenoiseClearScreen();
      refreshLine(l);
      break;
    case CTRL_W: /* ctrl+w, delete previous word */
      linenoiseEditDeletePrevWord(l);
      break;
  }
  return linenoiseEditMore;
}

/* This is part of the multiplexed linenoise API. See linenoiseEditStart()
 * for more information. This function is called when linenoiseEditFeed()
 * returns something different than NULL. At this point the user input
 * is in the buffer, and we can restore the terminal in normal mode. */
void linenoiseEditStop(struct linenoiseState *l) {
  if (!isatty(l->ifd)) return;
  disableRawMode(l->ifd);
  printf("\n");
}

/* This just implements a blocking loop for the multiplexed API.
 * In many applications that are not event-drivern, we can just call
 * the blocking linenoise API, wait for the user to complete the editing
 * and return the buffer. */
static char *linenoiseBlockingEdit(int stdin_fd, int stdout_fd, char *buf, size_t buflen, const char *prompt) {
  struct linenoiseState l;

  /* Editing without a buffer is invalid. */
  if (buflen == 0) {
    errno = EINVAL;
    return NULL;
  }

  linenoiseEditStart(&l, stdin_fd, stdout_fd, buf, buflen, prompt);
  char *res;
  while ((res = linenoiseEditFeed(&l)) == linenoiseEditMore)
    ;
  linenoiseEditStop(&l);
  return res;
}

/* This special mode is used by linenoise in order to print scan codes
 * on screen for debugging / development purposes. It is implemented
 * by the linenoise_example program using the --keycodes option. */
void linenoisePrintKeyCodes(void) {
  char quit[4];

  printf(
      "Linenoise key codes debugging mode.\n"
      "Press keys to see scan codes. Type 'quit' at any time to exit.\n");
  if (enableRawMode(STDIN_FILENO) == -1) return;
  memset(quit, ' ', 4);
  while (1) {
    char c;
    int nread;

    nread = read(STDIN_FILENO, &c, 1);
    if (nread <= 0) continue;
    memmove(quit, quit + 1, sizeof(quit) - 1); /* shift string to left. */
    quit[sizeof(quit) - 1] = c;                /* Insert current char on the right. */
    if (memcmp(quit, "quit", sizeof(quit)) == 0) break;

    printf("'%c' %02x (%d) (type quit to exit)\n", isprint(c) ? c : '?', (int)c, (int)c);
    printf("\r"); /* Go left edge manually, we are in raw mode. */
    fflush(stdout);
  }
  disableRawMode(STDIN_FILENO);
}

/* This function is called when linenoise() is called with the standard
 * input file descriptor not attached to a TTY. So for example when the
 * program using linenoise is called in pipe or with a file redirected
 * to its standard input. In this case, we want to be able to return the
 * line regardless of its length (by default we are limited to 4k). */
static char *linenoiseNoTTY(void) {
  char *line = NULL;
  size_t len = 0, maxlen = 0;

  while (1) {
    if (len == maxlen) {
      if (maxlen == 0) maxlen = 16;
      maxlen *= 2;
      char *oldval = line;
      line = realloc(line, maxlen);
      if (line == NULL) {
        if (oldval) free(oldval);
        return NULL;
      }
    }
    int c = fgetc(stdin);
    if (c == EOF || c == '\n') {
      if (c == EOF && len == 0) {
        free(line);
        return NULL;
      } else {
        line[len] = '\0';
        return line;
      }
    } else {
      line[len] = c;
      len++;
    }
  }
}

/* The high level function that is the main API of the linenoise library.
 * This function checks if the terminal has basic capabilities, just checking
 * for a blacklist of stupid terminals, and later either calls the line
 * editing function or uses dummy fgets() so that you will be able to type
 * something even in the most desperate of the conditions. */
char *linenoise(const char *prompt) {
  char buf[LINENOISE_MAX_LINE];

  if (!isatty(STDIN_FILENO)) {
    /* Not a tty: read from file / pipe. In this mode we don't want any
     * limit to the line size, so we call a function to handle that. */
    return linenoiseNoTTY();
  } else if (isUnsupportedTerm()) {
    size_t len;

    printf("%s", prompt);
    fflush(stdout);
    if (fgets(buf, LINENOISE_MAX_LINE, stdin) == NULL) return NULL;
    len = strlen(buf);
    while (len && (buf[len - 1] == '\n' || buf[len - 1] == '\r')) {
      len--;
      buf[len] = '\0';
    }
    return strdup(buf);
  } else {
    char *retval = linenoiseBlockingEdit(STDIN_FILENO, STDOUT_FILENO, buf, LINENOISE_MAX_LINE, prompt);
    return retval;
  }
}

/* This is just a wrapper the user may want to call in order to make sure
 * the linenoise returned buffer is freed with the same allocator it was
 * created with. Useful when the main program is using an alternative
 * allocator. */
void linenoiseFree(void *ptr) {
  if (ptr == linenoiseEditMore) return;  // Protect from API misuse.
  free(ptr);
}

/* ================================ History ================================= */

/* Free the history, but does not reset it. Only used when we have to
 * exit() to avoid memory leaks are reported by valgrind & co. */
static void freeHistory(void) {
  if (history) {
    int j;

    for (j = 0; j < history_len; j++) free(history[j]);
    free(history);
  }
}

/* At exit we'll try to fix the terminal to the initial conditions. */
static void linenoiseAtExit(void) {
  disableRawMode(STDIN_FILENO);
  freeHistory();
}

/* This is the API call to add a new entry in the linenoise history.
 * It uses a fixed array of char pointers that are shifted (memmoved)
 * when the history max length is reached in order to remove the older
 * entry and make room for the new one, so it is not exactly suitable for huge
 * histories, but will work well for a few hundred of entries.
 *
 * Using a circular buffer is smarter, but a bit more complex to handle. */
int linenoiseHistoryAdd(const char *line) {
  char *linecopy;

  if (history_max_len == 0) return 0;

  /* Initialization on first call. */
  if (history == NULL) {
    history = malloc(sizeof(char *) * history_max_len);
    if (history == NULL) return 0;
    memset(history, 0, (sizeof(char *) * history_max_len));
  }

  /* Don't add duplicated lines. */
  if (history_len && !strcmp(history[history_len - 1], line)) return 0;

  /* Add an heap allocated copy of the line in the history.
   * If we reached the max length, remove the older line. */
  linecopy = strdup(line);
  if (!linecopy) return 0;
  if (history_len == history_max_len) {
    free(history[0]);
    memmove(history, history + 1, sizeof(char *) * (history_max_len - 1));
    history_len--;
  }
  history[history_len] = linecopy;
  history_len++;
  return 1;
}

/* Set the maximum length for the history. This function can be called even
 * if there is already some history, the function will make sure to retain
 * just the latest 'len' elements if the new history length value is smaller
 * than the amount of items already inside the history. */
int linenoiseHistorySetMaxLen(int len) {
  char **new;

  if (len < 1) return 0;
  if (history) {
    int tocopy = history_len;

    new = malloc(sizeof(char *) * len);
    if (new == NULL) return 0;

    /* If we can't copy everything, free the elements we'll not use. */
    if (len < tocopy) {
      int j;

      for (j = 0; j < tocopy - len; j++) free(history[j]);
      tocopy = len;
    }
    memset(new, 0, sizeof(char *) * len);
    memcpy(new, history + (history_len - tocopy), sizeof(char *) * tocopy);
    free(history);
    history = new;
  }
  history_max_len = len;
  if (history_len > history_max_len) history_len = history_max_len;
  return 1;
}

/* Save the history in the specified file. On success 0 is returned
 * otherwise -1 is returned. */
int linenoiseHistorySave(const char *filename) {
  mode_t old_umask = umask(S_IXUSR | S_IRWXG | S_IRWXO);
  FILE *fp;
  int j;

  fp = fopen(filename, "w");
  umask(old_umask);
  if (fp == NULL) return -1;
  chmod(filename, S_IRUSR | S_IWUSR);
  for (j = 0; j < history_len; j++) fprintf(fp, "%s\n", history[j]);
  fclose(fp);
  return 0;
}

/* Load the history from the specified file. If the file does not exist
 * zero is returned and no operation is performed.
 *
 * If the file exists and the operation succeeded 0 is returned, otherwise
 * on error -1 is returned. */
int linenoiseHistoryLoad(const char *filename) {
  FILE *fp = fopen(filename, "r");
  char buf[LINENOISE_MAX_LINE];

  if (fp == NULL) return -1;

  while (fgets(buf, LINENOISE_MAX_LINE, fp) != NULL) {
    char *p;

    p = strchr(buf, '\r');
    if (!p) p = strchr(buf, '\n');
    if (p) *p = '\0';
    linenoiseHistoryAdd(buf);
  }
  fclose(fp);
  return 0;
}
